The invention relates to a differential and a differential system adapted for a four-wheel drive vehicle and, more specifically, to ones adapted for a vehicle mutually switchable between four-wheel drive and two-wheel drive.
Conventionally, a drive force transmission with a differential of Japanese Patent Application Laid-Open Publications No. 3-118233 and NO. 3-292437 are known.
The drive force transmission is located to a rear wheel drive system in a four-wheel drive system. The transmission has a differential with a rotatable differential housing. The transmission includes a ring gear member for the transmission of a drive force to the casing.
The ring gear member, however, is rotatably supported to another member such as a shaft, not the differential housing. During two-wheel drive, the sliding of the ring gear member on the differential housing or the shaft results in sliding resistance. This causes seizing and galling to generate drive resistance as drag torque for the reduction of the fuel cost of the engine.
It therefore is an object of the present invention to provide a differential and a differential system in which drive resistance reduces remarkably.
To achieve the object, a first aspect of the invention provides a differential. The differential includes a differential housing. The differential includes a torque transmission member supported to the differential housing for rotating relative to the differential housing. The differential includes a clutch system configured to interconnect between the torque transmission member and the differential housing for transmitting a drive torque therebetween.
The differential includes a non-limited slip differential and a limited slip differential (LSD). The LSD includes a corn-clutch type, a multiplate-clutch type, or a parallel-axis type.
Preferably, the differential further includes a support member located between the torque transmission member and the differential housing. The support member supports the torque transmission member to the differential housing for rotation.
The support member includes a bearing, a roller, and a ball. The bearing includes a ball bearing and a slide bearing.
Preferably, the support member and the clutch system are axially arranged to each other.
Preferably, the torque transmission member has a gear located in radial alignment with the support member.
Preferably, the clutch system includes a first clutch provided between the torque transmission member and the differential housing. The clutch system includes an actuator for operating the first clutch. The first clutch is located axially between the support member and the actuator.
The first clutch includes a dog clutch, and a friction clutch. The actuator includes a electromagnet type, and hydraulic type.
Preferably, the support member supports at least two points of the torque transmission member.
Preferably, the torque transmission member axially has an end. The actuator is located at the end. The first clutch is located axially back from the end.
Preferably, the support member is located in alignment with the clutch system.
Preferably, the actuator includes a second clutch for transmitting a drive torque from the torque transmission member. The actuator includes a converter provided between the first and second clutches for converting a drive torque to a thrust force and for engaging the first clutch.
Preferably, the actuator further includes an electromagnet system for engaging the second clutch.
Preferably, the electromagnetic system includes a core. The electromagnetic system includes a rotor located between the core and the second clutch for magnetically conducting therebetween. The rotor is supported on the differential housing.
Preferably, the converter includes a cam mechanism configured to be operated by the second clutch.
Preferably, the second clutch includes first clutch plates connected the torque transmission member, the first clutch plates being spaced from each other. The second clutch includes second clutch plates connected to the converter. Respective second clutch plates are slidably interposed between respective first clutch plates.
Preferably, the first clutch plates are spaced radially from the converter.
Preferably, the second clutch plates are spaced radially from the torque transmission member.
Preferably, the electromagnet system includes an armature configured to be attracted for pressing and engaging with the second clutch. The armature is spaced radially from the torque transmission member.
Preferably, the rotor has openings each extending within an angular range. The openings are angularly spaced from each other and are located radially inward of a coil of the electromagnet system.
Preferably, the openings face a core of the electromagnet system.
Preferably, the support member includes bearings arranged in axial alignment with each other.
A second aspect of the invention provides a differential system. The system includes a transmission mechanism for transmitting a drive torque. The system includes a differential. The system includes a torque transmission member supported to the differential for rotating relative to the differential. The system includes a clutch system configured to interconnect between the torque transmission member and the differential for transmitting a drive torque between the transmission mechanism and the differential.